Refrigeration



Nov. 4,1941.

w. T. HEDLUND REFRIGERATION Filed Aug. 10, 1937 2 Sheets-Sheet l Nov. 4, 1941. w. T. HEDLUNE REFRIGERA'Z'ICN Filed Aug. 10, 1937 2 Sheets-Sheet 2 ENIOR mum MML $11 i M/t W lfiTORVEY.

Patented Nov. 4, 1941 ire PTENT DFFI? REFRIGERATION William T. Hedlund, New Rochelle, N. Y., assignor to Servel, Inc., New York, N. Y., a corporation of Delaware 18 Claims.

My invention relates to refrigeration, and more particularly to cooling of a storage compartment of a refrigerator.

It is an object of my invention to provide an improvement for cooling a storage compartment of a refrigerator with the aid of a heat transfer system. I accomplish this by providing a heat transfer system which is associated with a cooling element and formed of tubular members connected to form a closed circuit adapted to contain a volatile fluid. The tubular members and volatile fluid therein form a heat transfer path which is arranged in a refrigerator storage compartment to occupy a minimum amount of usable storage space. I provide one or more tubular structures serving as a heat transfer system which may be employed to support shelves in the storage compartment of a refrigerator.

freezing unit and to eliminate the necessity of defrosting, the freezing unit is insulated.

The invention, together with the above and other advantages thereof, will be more fully understood from the following description taken in conjunction With the accompanying drawings forming a part of this specification and of which:

Fig. 1 diagrammatically illustrates a refrigeration system and a side vertical sectional view of a refrigerator embodying the invention;

Fig. 2 is a horizontal sectional view of the re frigerator shown in Fig. 1 and taken on line 2-2 of Fig. 3;

Fig. 3 is a vertical sectional view taken on line 33 of Fig. 2;

Fig. 4 is a perspective view illustrating more clearly the tubular structure arranged within the refrigerator shown in Figs. 1 to Binclusive;

Fig. 5 is a fragmentary perspective view of a tubular structure illustrating a modification of the invention; and

Fig. 6 is a fragmentary perspective view illustrating the manner in which a shelf may be supported on the tubular structure shown in Fig. 5.

Referring to Fig. 1, I have shown my invention I0 having an inner metal shell H arranged to be supported within an outer metal shell l2 and insulated therefrom with any suitable insulating material It. The inner metal shell H defines a thermally insulated storage compartment l5 into which access may be had by a door it hinged at the front of the cabinet. The storage comgartment i5 is provided with a plurality of shelves 1! for supporting food products which are preserved and maintained at a low temperature.

Within the storage compartment I5 is disposed a cooling unit iii. Although I do not wish to be limited thereto, the cooling unit l8 may form part of a refrigeration system of a uniform pressure absorption type, generally as described in Patent No. 2,037,782 to William R. Hainsworth. In a system of this type a refrigerant fluid, such as ammonia, is introduced through a conduit 24% into the cooling unit Hi. The refrigerant evaporates and diffuses in the cooling unit into an inert gas, such as hydrogen, to produce a relrigerating effect. The resulting gas mixture of refrigerant and inert gas flows from the upper part otcooling unit l8 through the inner passage of a gas heat exchanger 25 into the lower part of an absorber 26.

In absorber 26 refrigerant gas is absorbed by a suitable liquid absorbent, such as water, which enters through a conduit 21. The inert gas, which is practically insoluble and weak in refrigerant, is returned to the lower part of cooling unit l8 through the outer passage of the gas heat exchanger 25; and the enriched absorption liquid is conducted from absorber 26 through the outer passage of a liquid heat exchanger 28 into chamber 29 of a generator 30.

By heating generator 35, as by a gas burner 3!, for example, liquid is raised by vapor-lift action through conduit 32 into the upper part of a stand-pipe 33. Liberated refrigerant vapor embodied in a refrigerator comprising a cabinet entering stand-pipe 33 through conduit 32, and also the refrigerant vapor expelled from solution in stand-pipe 33 and chamber 34, flows upward into an air-cooled condenser 35. Refrigerant vapor is liquefied in condenser 35 and returned to cooling unit l8 through conduit 24 to complete the refrigerating cycle.

The weakened absorption liquid from which refrigerant has been expelled flows from chamber 34 through the liquid heat exchanger 28 and conduit 21 into the upper part of absorber '26. The heat liberated .with absorption of refrigerant vapor in absorber 28 is transferred to a cooling medium which flows through a coil 36 which is disposed about and in thermal relation with the absorber.

A vessel 31 is connected by a conduit 38 to the lower part of condenser 35 and by a conduit 38 to the gas circuit, as at absorber 26, so that any inert gas which may pass into the condenser can flow into the gas circuit. Refrigerant vapor not liquefied in condenser 35 flows through conduit 38 to displace inert gas in vessel 31 and force such gas through conduit 39 into the gas circuit, thereby increasing the total pressure in the system so that an adequate condensing pressure is obtained to insure condensation of refrigerant vapor in condenser 35.

The cooling unit It includes an upper coil 20 and a lower coil 2| which are connected in series relation. Liquid refrigerant entering the upper coil 20 through conduit 24 flows downward in counter-flow to inert gas which flows upward and enters the lower coil 2| from the outer passage of the gas heat exchanger 25. Since the inert gas flows first through the lower coil 2| and then through the upper coil 20, the gas in the upper coil contains a greater amount of refrigerant vapor than the gas in the lower coil. The partial pressure of refrigerant vapor is therefore higher in coil 20 than in coil 2|, and evaporation of liquid refrigerant takes place at a higher temperature in the upper coil than in the lower coil.

The upper coil 20 and lower coil 2| are pref. erably operated above and below the freezing temperature of water. The upper coil or cooling element 20, with the aid of a secondary cooling system I! to be described hereinafter, is utilized to effect cooling of the storage compartment IS. The lower coil or cooling element 2| may be embedded in or otherwise suitably arranged in heat exchange relation with a shell 22. The shell 22 is provided'with a plurality of compartments adapted to receive trays for freezing water and the like.

Since the lower coil 2| is operated below the freezing temperature of water, water vapor is condensed out of air if air is permitted to con.. tact the shell 22. The water vapor condensed in this manner freezes and forms a coating of frost on the shell '22. To prevent removal of water vapor from air by the shell 22, the latter is insulated with any suitable insulating material ill which is protected by an outer casing In accordance with my invention, in order to effectively utilize the upper cooling element or coil 20 for cooling the storage compartment I5, I provide theiheat transfer system Is. The heat transfer system H is in thermal exchange relation with upper coil 20 and formed of a plurlali'ty of tubular members. I employ separate tubular structures 4|) to form the heat transfer system II, the structures 40 being disposed at opposite sides of the storage compartment [5.

As shown most clearly in Fig. 4, each tubular structure 40 comprises vertically extending tubular members 4| and 42 which are connected to and in communication with horizontal tubular members 43. The upper ends of members 4| and 42 are connected to the opposite ends of a looped coil 44. In the heat transfer system I have provided, the looped coils 44 constitute condensation portions, the horizontal members 43 and portions of vertical members 4| and 42 constitute evaporation portions, and the upper parts of the members 4| and 42 constitute the conduits connecting the condensation and evaporation portions.

The looped coils or condensation portions 44 are arranged in good heat exchange relation with the upper coil or cooling element 20. I accomplish this by embedding the upper coil 20 in a metal casting 45 and the looped coils 44 in separate metal castings 45. The casting 45 is arranged in an opening at the top of easing 5| with the lower part thereof resting on the insulating material 50. The castings 45 bear'against the casting 45 and are effectively maintained in position by spring clamps 41, as shown most clearly in Fig. l. The space between the casing 5| and the top of the storage compartment i5 is eflectively sealed by side plates 48 having the inner surfaces thereof covered with an insulating material 49. The side plates 48 are removably secured at the top of casing 5|, whereby the tubular structures 40 may be inserted into and removed from the storage compartment I! through the front of the cabinet Ill.

The vertical tubular members 4| and 42 are disposed at the corners of and adJacent to the side walls of storage compartment 5. The upper parts of members 4| and 42 are also disposed adjacent to the walls of the storage compartment and the sides of cooling unit l8, so that the tubular structures 40 will occupy a minimum amount of usable storage space.

The horizontal members 43 may be employed to support the shelves I'I which are located below the cooling unit IS. The upper parts of members 4| and 42 may be shaped in any suitable manner, as shown in Figs. 3 and 4, whereby the horizontal portions thereof may be employed to support smaller shelves at each side of the cooling unit i8. If desired, the tubular structures 40 may be connected by additional tubular members 52 which are disposed below the shelf and in communication with the members 4| and 42,

as shown in dotted lines in Fig. 3.

The tubular structures 40 form closed fluid circuits which are partly filled with a volatile liquid. The amount of volatile liquid in the structures may be between one-half to two-thirds of their volumetric capacities. In operation, the volatile liquid, such as ethyl chloride, evaporates in the tubular structures and takes up heat, thereby effecting cooling of the compartment. The vapor flows upward into the looped coils 44 where it is cooled and condensed by the upper coil or cooling element 20. The condensate flows downward in the tubular structures and is again evaporated.

The conduits forming the tubular structures are of such size that the vapor bubbles freely pass liquid in the conduits. In other words, the internal diameter of the conduits is sufficiently large to prevent the vapor bubbles from lifting liquid in the lower parts of the tubular structures, and also sumciently large to permit gravity flow of liquid from the condensation portions 44.

Inasmuch as the tubular structures provide cooling or heat abstracting zones throughout the entire height of the storage compartment, solid shelves l'l may be employed to provide a plurality of smaller compartments for supporting and preserving food products. A suitable gasket 52 formed of rubber or the like may be provided about the periphery of each shelf i'l. Since the heat transfer system operates at a temperature above rather than below the temperature of water, and the freezing unit is insulated. less water vapor is removed from air and the dehydration of foods is lessened because the storage compartment is kept at a higher humidity,

The tubular structures 40 may be of any desired shape, and I do not wish to be limited to the particular arrangement of conduits shown and described above. In Figs. and 6 I have shown a modification of the tubular structures In which permits adjustment of the solid shelves II. In this modification the vertical members 4| and 42 are connected by an upper and lower horizontal members 43. The members ll and 42 are formed with spaced lugs 54. The shelves Il may be supported at the lugs It by rings or annular members 55 which are vertically movable along the members ll and 2. Each ring 55 is provided with an arm 58 having an upturned end 51 which flts into an opening in a corner of a shelf. When it is-desired to raise or lower a shelf, the ring 55 is turned or rotated to such a position that the opening 58 in the ring is opposite the lug 5| and will freely move past the latter.

The cooling unit 58 forms a part of refrigeration apparatus and the conduits connecting this part with other parts of the apparatus extend through a removal wall portion adjacent to the upper part of gas heat exchanger 25, as clearly shown in Fig. 1. When the looped coils or condensation portions M of the heat transfer system are detached from upper cooling element 29, the refrigeration apparatus including both elements 20 and- 2| of the cooling unit It can be removed with all parts of the heat transfer system remaining in their structural relationship to the storage compartment 65. Likewise, when the heat transfer system is removed from the storage compartment l5, after detaching the condensation portions 44 from upper cooling element 20, the latter will remain in its structural relationship to the compartment. When the condensation portions 44 are in heat exchange relationship with upper cooling element 20 and in functioning relationship therewith, cooling effect is transmitted to the looped coils forming the condensation portions. Heat is conducted through the heat transfer system to transmit cooling effect to the smaller compartments formed by the solid shelves I I.

The provision of a heat transfer system of the character described is extremely flexible and takes up a minimum amount of usable storage space. Instead of providing a single cooling region having the necessary heat transfer surface to effect cooling of the storage compartment, the use of the heat transfer system described above provides cooling surfaces which are distributed throughout the compartment to provide a pinrality of cooling zones or regions. By locating these cooling zones adjacent the corners and side walls of the storage compartment, the amount of usable storage space is not materially reduced. The cooling element of the refrigeration system which provides a single cooling zone and is normally employed to cool the storage compartment may therefore be reduced in size and arranged to occupy a minimum amount of space. This either provides additional storage space when the size of the freezing unit remains unchanged, or permits increasing the size of the freezing unit without further decreasing the amount of usable storage space in the compartment.

Although I have shown and described particular embodiments of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made, and that certain features may be employed independently of others, without departing from the spirit a higher temperature in said second section, and

a'system for a heat transfer fluid and comprising a heat rejecting portion in thermal exchange relation with said second section and a heat abstracting portion, one or more shelves external to said system, said heat abstracting portion including conduits connected and arranged to support said shelf or shelves in said compartment.

2. Apparatus as set forth in claim 1 wherein said shelf or shelves are solid to divide said compartment into a plurality of smaller compartments between which circulation of air is restricted, and different parts of said heat abstracting portion are located in one'or more of said smaller compartments.

3. Apparatus as set forth in claim 1 in which said second section of said' evaporator is at a higher level than said first section and said heat abstracting portion of said system for heat transfer fluid is at a lower level than said first section.

4. A refrigerator having a thermally insulated storage compartment provided with an opening, a door for closing the opening, a cooling element in said compartment, a heat transfer system containing a volatile fluid and having a condensation portion and a vaporization portion, one or more shelves in said compartment and external to said heat transfer system, said heat transfer system comprising conduits connected and arranged to support said shelf or shelves in said compartment and being insertable into the latter through the opening, and means for removabiy connecting said condensation portion in thermal exchange relation with said cooling element.

5. Ina refrigerator as set forth in claim 4,

means for insulating said condensation portion to said vaporization-condensation circuit, said shelf or shelves dividing said compartment into a plurality of smaller compartments in one of which said low temperature cooling element is disposed, said circuit including a vaporization portion comprising conduits in heat transmitting relation to a plurality of said smaller compartments including said compartment in which said low temperature cooling element is disposed for transmitting cooling effect thereto, said conduits being connected and arranged to support said shelf or shelves, and a condensation portion ar- 1 therefore aim in ranged in thermal exchange relation with said higher temperature cooling element 7. In a refrigerator having a thermally insulated storage compartment, refrigeration apparatus including a low temperature cooling element and a higher temperature cooling element both disposed in said compartment, a heat transfer system containing a volatile fluid and including a vaporization portion and a condensation portion, one or more shelves in said compartment external to said heat transfer system, said shelf or shelves dividing said compartment into a plurality of smaller compartments in one of which said low temperature cooling element is disposed,

said condensation portion being arranged in thermal exchange relation with said higher temperature cooling element and said vaporization portion comprising conduits in heat transmitting relation to one of said smaller compartments, other than said smaller compartment in which said low temperature cooling element is disposed, for transmitting cooling effect thereto, said conduits being connected and arranged to support said shelf or shelves.

8. In a refrigerator having a thermally insulated storage compartment, refrigeration apparatus including a low temperature cooling ele-- ment and a higher temperature cooling element, structure including one or more shelves in said compartment for dividing the latter into a plurality of smaller compartments and a conduit system for supporting said shelf or shelves, said shelf or shelves being external to said conduit system, said system having a portion thereof in thermal exchange relation with said higher temperature cooling element and being partly filled with a volatile liquid, andsaid conduit system being in' heat transmitting relation to one or more of said smaller compartments to transfer cooling effect thereto, said low temperature cooling element being located and arranged so that transfer of cooling effect therefrom to one or more of said smaller compartments is impeded.

9. In a refrigerator having a thermally insulated storage compartment, one or more shelves in said compartment, a conduit system partly filled with a volatile liquid and including vertically extending members provided with catches at different elevations, and supports for said shelf or shelves adapted to rest on said catches and turnable and vertically adjustable along said members past said catches without the use of tools.

10. In a thermally insulated storage compartment, one or more shelves in said compartment, a cooling element, a circuit containing a heat transfer fluid and comprising a heat rejecting portion removably connected to said cooling ele- -ment and a heat absorbing portion including spaced conduits, structure comprising said conduits for supporting said shelf or shelves in said compartment, said structure including supporting means adjustable to different positions along said conduits whereby said shelf or shelves are adjustable to diflerent levels, said circuit including said heat rejecting portion and said heat absorbing portion constituting a removable unit,

and said cooling element being arranged so that with said cooling element whereby said cooling element transmits cooling effect to said condensation portion when in functioning relationtion and at least the portion of said cooling element in thermal exchange relation with said condensation portion, one or-more solid shelves dividing said compartment. into a plurality of smaller compartments between which circulation of air is restricted, and said vaporization portion including fluid passages in heat transmitting relation to one or more of said smaller compartments for transferring cooling effect thereto, said heat transfer circuit including said vaporization portion and condensation portion constituting a removable structure, and said refrigeration apparatus including said cooling element being arranged so that they may remain in their structural relationship to said storage compartment upon removal of said structure.

12. In a refrigerator including a cabinet having a compartment, a cooling element, structure providing a heat transfer system at least partly supported by the bottom of said compartment, 'said system being filled with a volatile liquid and including a vaporization portion and a condensation portion having a removable connection with said cooling element whereby said cooling element transmits cooling effect to said condensation portion when in functioning relationship, one or more shelves in said compartment, said vaporization portion including spaced vertically extending conduits disposed adjacent the side walls of said compartment for transferring cooling effect to the latter, said conduits being arranged to support said shelf or shelves in said compartment, .said heat transfer system including said vaporization portion and said condensation portion constituting a removablestructure,

and said cooling element being arranged so that it may remain in its structural relationship to said compartment upon removal of said structure. r 13. In a refrigerator including a cabinet having a thermally insulated food space, a cooling element, a heat transfer circuit containing a volatile fluid and having a removable connection with said cooling element whereby said cooling element transmits cooling effect to said circuit when in functioning relationship, means including one or more solid shelves external to said heat transfer circuit and dividing said space into a plurality of compartments between which circulation of air is restricted, said heat transfer circuit including a plurality of vertically extending conduits disposed adjacent the walls of said space, means including said conduits for supporting said shelf or shelves, said conduits being in heat transmitting relation to one or more of said compartments for transferring cooling effect thereto, and said heat transfer circuit including said vertically extending conduits constituting a removable structure, and said cooling element being arranged so that it may remain in its structural relationship to said space upon removal of said structure.

14. In a refrigerator including a cabinet having a thermally insulated storage compartment, refrigeration apparatus including a-cooling element, a heat transfer circuit partly filled with a volatile liquid and including a vaporization portion and a condensation portion having a removable connection with said cooling element whereby said cooling element transmits cooling effect to said condensation portion when in functioning relationship, said cooling element and said condensation portion being thermally segregated from said compartment, one or more solid shelves dividing said compartment into a plurality of smaller chambers between which circulation of air is restricted, said vaporization portion including fluid passages in heat transmitting relation to one or more of said smaller chambers for transferring cooling effect thereto, said refrigeration apparatus including said cooling element constituting a removable unit, and said shelf or shelves and said heat transfer circuit being arranged so that they may remain in their structural and cooling effect transmission relationship to said compartment upon removal of said unit.

15. In a refrigerator including-a cabinet having a thermally insulated storage compartment provided with a solid shelf dividingthe compartment into upper and lower chambers between which circulation of air is restricted, refrigeration apparatus including a cooling element in said upper chamber, a heat transfer circuit "containing a volatile fluid and having a removable connection with said cooling element whereby said element transmits cooling effect to said circuit when in functioning relationship, and one or more shelves in said lower chamber, said heat transfer system including members connected and arranged to support said shelves and also arranged to transfer cooling effect to said lower chamber, said heat transfer circuit including said members constituting a removable structure, and said refrigeration apparatus including said cooling element being arranged so that they may remain in their structural relationship to said compartment upon removal of said structure.

16. In a refrigerator including a cabinet provided with an inner liner member forming a food storage compartment having an opening at the front of the cabinet, the compartment having one or more shelves therein, the top and bottom of the liner member being spaced apart substantially the height of the rear and lateral side walls thereof, refrigeration apparatus includin a cooling element in said compartment, the cooling element having a chamber adapted to receive matter to be refrigerated, a door for the opening for inserting: and removing food products and the like into and from the compartment and also afiording access to the chamber of the cooling element, a heat transfer circuit including metallic members in heat transmit-- ting relation to said compartment for transferring cooling effect thereto, said circuit con- ;taining a volatile fluid and having a removable connection with said cooling element whereby said cooling element transmits cooling effect to said circuit when in functioning relation, said metallic members being formed and arranged to support said shelf or shelves in said compartment, said refrigeration apparatus including said cooling element constituting a removable unit, and said heat transfer circuit including said metallic members being arranged so that they may remain in their structural and cooling ef- Y opening for inserting and removing food products and the like into and from the compartment and also affording access to the chamber of the cooling element, metallic members in heat transfer relation to said compartment for transferring cooling effect thereto, a heat conductor in direct heat transmitting relation with said metallic members for transmitting cooling effect thereto, said heat conductor having a removable connection with said cooling element whereby said cooling element transmits cooling effect to said heat conductor when in functioning relationship, said metallic members being constructed and arranged to support said shelf or shelves in said compartment, said refrigeration apparatus including said cooling element constituting a removable unit, and said metallic members and said heat conductor being arranged so that they may remain in their structural and cooling effect transmission relationship to said compartment upon removal of said unit.

18. In a refrigerator including a cabinet provided with an inner liner member forming a food storage compartment having an opening at the front of the cabinet, the compartment having one or more shelves therein, the top and bottom of the liner member being spaced apart substantially the height of the rear and lateral side walls thereof, refrigeration apparatus including a cooling element in said compartment, the cooling element having a chamber adapted to receive matter to be refrigerated, a door for the opening for inserting and removing food products and the like into and from the compartment and also affording access to the chamber of the cooling element, metallic members in said compartment for transferring cooling effect thereto, a heat conductor in direct heat transmitting relation with said metallic members for transmitting cooling effect thereto, said heat conductor having a removable connection with said cooling element whereby said cooling element transmits cooling effect to said heat conductor when in functioning relationship, said.

metallic members being formed and arranged to support said shelf or shelves in said compartment, said heat conductor and said metallic members constituting a removable structure, and said refrigeration apparatus including said cooling element being arranged so that they may remain in their structural relationship to said compartment upon removal of said structure.-

WILLIAM T. HEDLUND. 

